Evaluation of Reservoir Compartmentalization Using Seismic Pore Pressure Modeling in an Oil Field in Persian Gulf

2020 ◽  
Author(s):  
P. Adabnezhad ◽  
A. Mollajan ◽  
F. Forghani
Keyword(s):  
Pore Pressure ◽  
Persian Gulf ◽  
Oil Field ◽  
Reservoir Compartmentalization

Impact of High Resolution 3D Geomechanics on Well Optimization in the Southern Gulf of Suez, Egypt

2021 ◽  
Author(s):  
Mohamed Elkhawaga ◽  
Wael A. Elghaney ◽  
Rajarajan Naidu ◽  
Assef Hussen ◽  
Ramy Rafaat ◽  
...  
Keyword(s):  
High Resolution ◽  
Pore Pressure ◽  
Cost Optimization ◽  
Oil Field ◽  
Wellbore Stability ◽  
Gulf Of Suez ◽  
Geomechanical Model ◽  
3D Geomechanical Model ◽  
The Cost ◽  
The Impact

Abstract Optimizing the number of casing strings has a direct impact on cost of drilling a well. The objective of the case study presented in this paper is the demonstration of reducing cost through integration of data. This paper shows the impact of high-resolution 3D geomechanical modeling on well cost optimization for the GS327 Oil field. The field is located in the Sothern Gulf of Suez basin and has been developed by 20 wells The conventional casing design in the field included three sections. In this mature field, especially with the challenge of reducing production cost, it is imperative to look for opportunites to optimize cost in drilling new wells to sustain ptoduction. 3D geomechanics is crucial for such cases in order to optimize the cost per barrel at the same time help to drill new wells safely. An old wellbore stability study did not support the decision-maker to merge any hole sections. However, there was not geomechanics-related problems recorded during the drilling the drilling of different mud weights. In this study, a 3D geomechanical model was developed and the new mud weight calculations positively affected the casing design for two new wells. The cost optimization will be useful for any future wells to be drilled in this area. This study documents how a 3D geomechanical model helped in the successful delivery of objectives (guided by an understanding of pore pressure and rock properties) through revision of mud weight window calculations that helped in optimizing the casing design and eliminate the need for an intermediate casing. This study reveals that the new calculated pore pressure in the GS327 field is predominantly hydrostatic with a minor decline in the reservoir pressure. In addition, rock strength of the shale is moderately high and nearly homogeneous, which helped in achieving a new casing design for the last two drilled wells in the field.

Revisiting the Classical Experiment in Earthquake Control at the Rangely Oil Field, Colorado, 1970, Using a Coupled Flow and Geomechanical Model

2021 ◽  
Author(s):  
Josimar A. Silva ◽  
Hannah Byrne ◽  
Andreas Plesch ◽  
John H. Shaw ◽  
Ruben Juanes
Keyword(s):  
Pore Pressure ◽  
Oil Field ◽  
Coupled Flow ◽  
Injection Wells ◽  
Rock Types ◽  
Pressure Diffusion ◽  
Main Fault ◽  
Injection Interval ◽  
Using Data ◽  
Pressure Changes

ABSTRACT The injection experiment conducted at the Rangely oil field, Colorado, was a pioneering study that showed qualitatively the correlation between reservoir pressure increases and earthquake occurrence. Here, we revisit this field experiment using a mechanistic approach to investigate why and how the earthquakes occurred. Using data collected from decades of field operations, we build a geological model for the Rangely oil field, perform reservoir simulation to history match pore-pressure variations during the experiment, and perform geomechanical simulations to obtain stresses at the main fault, where the earthquakes were sourced. As a viable model, we hypothesize that pressure diffusion occurred through a system of highly permeable fractures, adjacent to the main fault in the field, connecting the injection wells to the area outside of the injection interval where intense seismic activity occurred. We also find that the main fault in the field is characterized by a friction coefficient μ  ≈  0.7—a value that is in good agreement with the classical laboratory estimates conducted by Byerlee for a variety of rock types. Finally, our modeling results suggest that earthquakes outside of the injection interval were released tectonic stresses and thus should be classified as triggered, whereas earthquakes inside the injection interval were driven mostly by anthropogenic pore-pressure changes and thus should be classified as induced.

Calculation and Analysis of Rock Stress State near the Bit

2012 ◽  
Vol 594-597 ◽  
pp. 65-69
Author(s):  
Wei Li ◽  
Tie Yan ◽  
Si Qi Li ◽  
Ling Zhang ◽  
Xing Hua Xu
Keyword(s):  
Stress State ◽  
Pore Pressure ◽  
Penetration Rate ◽  
Oil Field ◽  
Rock Stress ◽  
Concentrated Force ◽  
Underbalanced Drilling ◽  
Permeable Rock ◽  
Mechanics Characteristic ◽  
Column Pressure

Underbalance drilling has been applied to each oil field at home and abroad, due to the advantage of increasing the penetration rate substantially, protecting the reservoir effectively and reducing the drilling costs. But in respect of rock stress state characteristics near the bottom, relatively speaking, the study was rarely.Take the borehole near the bottom in underbalance drilling as the research object, analyze the influence of terrestrial stress, pore pressure and fluid column pressure on mechanics characteristic of rock in the bottom, to study the rock crushing efficiency, well deviation and hole stability of non-permeable wellbore and permeable wellbore in underbalanced drilling. The result shows that the mechanical properties of rocks near the bottom are subject to terrestrial stress, pore pressure and fluid column pressure. In non-permeable rock, the rock crushing efficiency, the penetration rate and the concentrated force of well trend to increase, the well trends to inclination. In permeable wellbore, with the permeability increasing, the rock crushing efficiency, the penetration rate and the concentrated force of well trend to decrease, the tendency of inclination becomes lower.

scholarly journals Development of 1D-Synthetic Geomechanical Well Logs for Applications Related to Reservoir Geomechanics in Buzurgan Oil Field

2021 ◽  
Vol 54 (2F) ◽  
pp. 74-88
Author(s):  
Qahtan Jubair ◽  
Farqad Hadi
Keyword(s):  
Neural Network ◽  
Mechanical Properties ◽  
Artificial Neural Network ◽  
Pore Pressure ◽  
Shear Wave ◽  
Oil Field ◽  
Well Logs ◽  
Production Section ◽  
Reservoir Geomechanics ◽  
Rock Mechanical Properties

Knowledge of the distribution of the rock mechanical properties along the depth of the wells is an important task for many applications related to reservoir geomechanics. Such these applications are wellbore stability analysis, hydraulic fracturing, reservoir compaction and subsidence, sand production, and fault reactivation. A major challenge with determining the rock mechanical properties is that they are not directly measured at the wellbore. They can be only sampled at well location using rock testing. Furthermore, the core analysis provides discrete data measurements for specific depth as well as it is often available only for a few wells in a field of interest. This study presents a methodology to generate synthetic-geomechanical well logs for the production section of the Buzurgan oil field, located in the south of Iraq, using an artificial neural network. An issue with the area of study is that shear wave velocities and pore pressure measurements in some wells are missing or incomplete possibly for cost and time-saving purposes. The unavailability of these data can potentially create inaccuracies in reservoir characterization n and production management. To overcome these challenges, this study presents two developed models for estimating the shear wave velocity and pore pressure using ANN techniques. The input parameters are conventional well logs including compressional wave, bulk density, and gamma-ray. Also, this study presents a construction of 1-D mechanical earth model for the production section of Buzurgan oil field which can be used for optimizing the selected mud weights with less wellbore problems (less nonproductive time. The results showed that artificial neural network is a powerful tool in determining the shear wave velocity and formation pore pressure using conventional well logs. The constructed 1D MEM revealed a high matching between the predicted wellbore instabilities and the actual wellbore failures that were observed by the caliper log. The majority of borehole enlargements can be attributed to the formation shear failures due to an inadequate selection of mud weights while drilling. Hence, this study presents optimum mud weights (1.3 to 1.35 g/cc) that can be used to drill new wells in the Buzurgan oil field with less expected drilling problems.

Critically stressed fractures: analysis of the Shaikan Field, Kurdistan Region of Iraq

2020 ◽  
Vol 177 (6) ◽  
pp. 1315-1328
Author(s):  
Callum J. D. Gilchrist ◽  
John W. Cosgrove ◽  
Kevin J. Parmassar
Keyword(s):  
Pore Pressure ◽  
Fractured Reservoirs ◽  
Significant Proportion ◽  
Fracture Network ◽  
Maximum Principal Stress ◽  
Oil Field ◽  
Reservoir Rock ◽  
Kurdistan Region ◽  
Previous Theory ◽  
Content Type

The Shaikan Field is a large producing oil field in the Kurdistan region of Iraq. It consists of multiple fractured reservoirs consisting of limestones, calcareous sandstones and mudstones. The surrounding tectonic terrane is situated in the seismically active Zagros–Taurus orogenic zone, where present-day stresses are high. The regional stresses are found to impose conditions that satisfy failure along reservoir-bound fractures, suggesting that a significant proportion of fractures are likely to be critically stressed. The in situ maximum principal stress magnitudes are estimated using three methods, namely, the tensile and compressive strengths of reservoir rock, and leak-off test (LOT) data. Stress-field orientations are determined from wellbore image log data, which are used to interpret wellbore breakouts and the associated induced tensile fractures. Reservoir pressure has declined since production started and poroelastic responses have been assessed and used to estimate the present-day stress-state and the criticality of those fractures that are most likely to fail or slip. Although a conventional approach has been used the present authors argue that a new approach to stress response with changing pore pressure should be taken. Unlike the previous theory of criticality in which a reduction in pore pressure is considered to lead to a stabilization of the fracture network, the present study suggests that a system may remain critically stressed regardless of pressure decline.Thematic collection: This article is part of the The Geology of Fractured Reservoirs collection available at: https://www.lyellcollection.org/cc/the-geology-of-fractured-reservoirs

3-D pore pressure prediction using seismic data in an oil field in southwest Iran

2008 ◽  
Author(s):  
Ehsan Nosrat ◽  
Abdolrahim Javaherian ◽  
Mahmoud Reza Torabi and Homayoun Behzad Asiri
Keyword(s):  
Pore Pressure ◽  
Seismic Data ◽  
Oil Field ◽  
Pore Pressure Prediction ◽  
Southwest Iran
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